The existing Gamma-ray radiating unit, as a key component of a medical device used in nuclear actinotherapy-Gamma cutter system, in regard to its configuration, includes a source body consisting of a number of radiation sources, and the source body is mounted in an antiradiation protection shielding case with its beam channels being directed radically toward a common focal point, such as what is described in European Patent Publication EP-248774. Since the Gamma cutter employs multiple radiation sources each with only a small dosage of radiation, it provides the maximum radiation energy only at the common focal-point, so that the tissue with pathological changes at the focal point will be effectively killed without any harm to its surrounding healthy tissues in certain period of time. Based on this consideration, the existing Gamma-ray radiation unit uses as many radiation sauces as possible, for example, in Leksell Gamma Cutter produced by Swedish ELEKTA Company, there are 201 radiation sources arranged regularly on a hemisphere. With quite a number of radiation sources and the correspondingly increased use of heavy metallic shielding materials, both the weight and the volume of such Gamma cutter will be enormous. In terms of manufacturing, to orderly and accurately make hundreds of holes having a common focal point on a hemisphere with quite a large diameter calls for rigorous technical measures and technological equipment. And since the source body is fixed in the shielding case, and its Gamma rays, even with smaller radiation energy, statically focus on the tissue of pathological changes, still needing to continuously get through healthy tissues to reach the focus of infection, harms will inevitably be caused to healthy tissues due to the progressive accumulation of radiation time.